FiOS QAM question

[philhu]

I live in Boston, and did a scan of the raw cable for QAM with my new Samsung 37" tv

I get quite a bit, all locals, sd and hd, weather channel, WGN-America, about 5-6 other channels, and all of music choice. Yippee!

My question though....
The new tv puts the locals on the right channels, like 4-1, 5-1, 7-1 etc. The HD ones are on 62-004,62-005,62-007, etc. The weatherchannel and others and music choice are on wierd channel numbers like 64-115, 72-31706, etc.

Now it gets wierd. My OTHER QAM ready tv, a 73" Mits DLP...I scanned them there and it gets the same channels, but on wierd numbers! And different numbers! The 4-1, 5-1, 7-1 etc are on wierd looking numbers too, like 48-704, 48-705, 48-707

Why would one QAM compatible TV show these right and another show them wrong? Any ideas?

 

[JPL]

With digital broadcast (either OTA or with QAM), there's metadata (PSIP) associated with your TV feeds. Part of that metadata includes channel mappings. So when you turn on channel 4-1, the feed really isn't in that frequency slot. It's elsewhere, but the PSIP information tells your TV to map 4-1 to the appropriate frequency slot. The weird numbers you're seeing are the actual frequency slots for those channels. So, channel 4-1 may be the mapped version of what's at frequency slot 48-704, e.g. Your first TV appears to be getting a mix of mapped and unmapped channels. So, why do you get that mix? That's because these providers aren't great at doing that PSIP mapping properly. My wife's grandparents have comcast basic cable with an HDTV. They scan in the clear QAM digital channels that they get. Some get mapped correctly, others don't.

Second, as to why one TV does a better job than the other (your second TV doesn't appear to be doing ANY channel mappings) - that's probably due to the TV itself. The firmware for each TV make is going to be different. It could be that the firmware on your second tv isn't up to snuff.

 

[philhu]

That makes total sense.

The Mits is a 1.5 yr old set and the Samsung is new, so the former might be not 'up to snuff'

I will call Mits. Maybe there is a firmware upgrade for it!

Phil